Vacuum stripper for cartons



` Nov. 19, 1940. J MUNN ETAL 2,221,990

VACUUMy STRIPPER FOR CARTONS Filed April 7, l959 @Zanden Patented Nov. 19, 1940 UNITED STATES VACUUM- STRIPPER FOR CARTONS John Munn and Alexander H. Burnett, Chicago, Ill.

Application April 7, 1939, Serial No. 266,654

12 Claims.

Our invention relates to means for removing cartons from a forming machine, and deals particularly with the machine covered in our Patent No. 2,135,409 dated November 1, 1938.

5 In the patent above referred to a set of strippers was employed which operated by gravity to discharge each carton as completed, and it is our main object to improve the stripping mechanism in a manner to insure the prompt and complete discharge of the finished carton at the proper time and place.

A further object of our improvement is to employ a simple vacuum system to retain the strippers in inactive positions when they are not in use, and provide means for the quick projection of the strippers on the release of the vacuum.

Another object of the invention is to provide a mechanism which is fullyautomatic, simple and inconspicuous.

With the above objects in view, and any others which may suggest themselves from the description to follow, a better understanding of the invention may be had by reference to the accompanying drawing, in which- Fig. 1 is an elevation of the rotary spider ernployed in the patented machine and in the improved form;

Fig. 2 is an enlarged fragmental section on the line 2--2 of Fig. 1; and

Fig. 3 is a section on the line 3-3 of Fig. 2.

In accordance with the foregoing, specific reference to the drawing indicates the shaft for the stripper spider at 3|, the hub plate for the spider being indicated at 3|c and the spider armsat 34. A fragment of the framework of the machine is shown, the same having a pendent-bearing bracket 30e to journal the shaft 3|. The latter also receives the pulley 3|a for the driving :of the spider in the manner indicated in Figs. 1 and 2 of the aforesaid patent.

For the purpose of our improvement the shaft 3| is made hollow in its outward portion, as indicated at 3|h. to receive a stationary tube 55 with a close sliding lit, the tube 55 taking a down bend 55a which is led to an exhaust pump (not shown).

The tube 55 has a series of circularly-spaced openings 55h, and the shaft 3| has a similarly arranged series of perforations 56 which are adapted to come into registration with the openings 55b as the shaft turns. The openings and perforations are equal in number, corresponding to the number of spider arms 34, which in the present instance is four.

The hub plate 3lc is fast on the shaft 3| and (Cl. 93-5L1) has a number of radial passages 51 extending from the perforations 56. Each passage 51 is formed with a lateral branch 58 toward the hub plate and'leading into a radial tube 59 which extends along the'related spider arm 34 to the 5 zone of the stripper.

As seen in Fig. 1, the stripper 35 is a block extended in' the circular path at the outer portions of the spider arms in the direction of rotation, which is indicated by arrows adjoining the hub 10 plate 3|c. The tube 59 leads into a passage 6I in the block 35, such passage opening into a longitudinal cylindrical compartment 62. This compartment has a restricted portion 63 near the end of the block followed by an enlarged outlet 15 64. A piston 65 is slidable in the compartment 62, the back of the piston being hollow as indicated at 66 to seat an expansive spring 61 directed from the back of the compartment and effective to keep the piston seated against the internal fg'o shoulder 63 of the compartment. The piston is extended outwardly with the rod 50a and plunger 50, as in the aforesaid patent, the object of the enlarged outlet 64 being to ushly seat the plunger when the same is in the retracted or in- 525 active position.

In our patent we depended upon gravity to cause the plunger 50 to advance and strip the carton from the block 35, but find that this action is at times sluggish or uncertain, so that it 53h is not of a uniform character. We have therefore provided the vacuum method of control and means to timethe same accurately as Wellas to operate the strippers quickly. v

Accordingly, with a constant vacuum tendency is; in the tube 55, the effect is to draw through the tubes 59 every time the spider arm passages 51 come in line with the tube openings 55h, with the result of drawing the plungers 50 of the respective blocks 35 inwardly to flush position and compressing the springs 61 behind them. The blocks can thus negotiate and propel the cartons during their formation without incident. However, each passage 51 is formed with an outlet 68 controlled by a spring-seated valve 69, the latter having an 245 outward control arm 10. The bearing arm 36e' carries a bracket 1| formed with a terminal cam 12 in the rotary path of the control arms 10. However, the position of the cam is such as to trip each arm when the block 35 corresponding thereto is in a vertical position. The right-hand block in Fig. 1 would be in such a position if its spider arm were to recede to about 30 degrees behind its shown position. Naturally, when the block 35 is in the vertical position, the conditions 55 are most favorable to the downward stripping of the carton, and this occurs by the quick, automatic projection of the plunger 50 by its spring 61 to the position shown, on the release of the 5 vacuum by the valve 69 as its arm 10 is tripped. Thus, Fig. 2 indicates the relative positions of the parts when such a release is procured, showing that the perforations 5B of the shaft 3i are closed to the tube55 at, such time. Y It will be evident from the above `description that we have provided a simple and eective means for operating the strippers. The vacuum connection is central and therefore common to all the spider arms; also such connection is v ery compact because of its inclusion in the shaft 3|. Beyond the vacuum connection the leads along the spider arms are small and therefore inconspicuous, and the blocks 35 and plungers 5!! show or carry nothing at all on the outside to indicate their special mechanism. Yet, it will be appreciated that with the systemproperly timed, the discharge of the carton can be regulated or placed wherever it is to the best advantage, and such discharge is sure to be quick because of the reex action of the springs 61 when the vacuum is released. Altogether, the mechanism is a simple and inconspicuous development in the scheme of the rotating spider to make the stripping action automatic and therefore adaptable for the rapid operation of the machine.

While we have described the improvement along specific lines, various minor changes and refinements may be made without departing from the principle of the invention, and we de- 35 sire to consider all such changes and renements as coming within the scope and spirit of the appended claims. We claim: 1. A stripper for a carton-propelling block 40 comprising a plunger, vacuum means for retaining the same in retracted position, and second means effective on the release of the vacuum means to advance the plunger against the carton to eject the same.

2. The structure of claim l, said second means comprising a spring compressed by the plunger on retraction.

3. A stripper for a carton-propelling block having a bore substantially in the path of its moveo ment comprising a piston slidable in said bore, a vacuum lead communicating with the latter and effective to retain the piston in retracted position,

a plunger carried by the piston and positioned flush with the front of the block when the piston isretracted, and means to advance the piston on the release of the vacuum and cause the plunger to eject the carton.

4. The structure of claim 3, said means being an expansive spring between the back of the pis- 6.0 ton and the rear end of said bore.

5. A stripper system for a series of carton-propelling blocks carried by the arms of a rotary-y spider comprising plungers in the blocks, vacuum means extending along the spider arms to `tne 6.5 respective blocks and effective to retain the plungers in retracted positions, second means to release the vacuum for a given block when the same reaches a position favorable for stripping the carton, and means effective on said release to advance the plunger of said block against the carton to eject the same.

6. A stripper system for a series of carton-propelling blocks carried by the arms of a rotary spider comprising plungers in the blocks, vacuum means extending along the spider arms to vthe respective blocks and effective to retain the plungers in retracted positions, second means to release ,the vacuum for al given block when the samev reaches'a position where the stripping of the carton is in a downward direction, and means effective on said release to advance the plunger of said block against the carton to eject the same.

7. A stripper system for a series of carton-propelling blocks carried by the anms of a rotary spider comprising plungers in the blocks, vacuum means extending along the spider arms to the respective blocks and effective to retain the plungers in retracted positions, second means to release the vacuum for a given block when the same reaches a position favorable for stripping the carton, and means within the block and effective on said release to advance the plunger of said block against the carton to eject the same.

8. A stripper system for a series of carton propelling blocks carried by the arms of a rotary spider comprising plungers in the blocks, vacuum ducts leading from the blocks to a Zone in the center of the spider, control means for said ducts and effective to release the vacuum in a given duct when the block related thereto reaches a position favorable for stripping the carton, and means `eiective on said release to advance the plunger of said block against the carton to eject the same, said control means including a distributor carried axially by the spider and connecting with each of said ducts, and a vacuum main leading to the distributor.

9. The structure of claim 8, said distributor being a tubular shaft with an annular series of openings leading-into the several ducts.

10. The structure of claim 8, said distributor being a tubular shaft with an annular series of openings leading into the several ducts, and said main being a tube telescoped in the shaft and formed with an annular series of perforations with which the distributor openings successively register on the rotation of the spider.

111. The structure of claim 8, said distributor being a tubular shaft with an annular series or openings leading into the several ducts, said main being a tube telescoped in the shaft and formed with an annular series 'of perforations with which the distributor openings successively vregister on the rotation of the spider, valves for said openings, and elements to periodically open the valves on the rotation of the spider.

12. The structure of claim 8, said distributor being a tubular shaft with an annular series of openings leading into the several ducts, said main being a tube telescoped in the shaft and formed with an annular series of perforations with which the distributor openings successively register on the rotation of the spider, valves for said openings, and a cam located in the rotary path of each valve to momentarily open the same.

JOHN MUNN. ALEXANDER H. BURNETT. 

